Shade rollers are widely used on balconies or windows to reach a purpose of blocking the sun or on indoor-walls to enrich the color of the room. Most shade rollers are provided with an ability that when the shade is pulled down to an extent, a fitting device mounted within the roller is able to maintain the shade at that extent, and when the shade no longer needs to be drawn, a user will only need to pull down the shade slightly and then release it, whereby the shade roller is able to roll back the shade automatically due to the recovery force stored within the roller when rotated to allow extension of the shade.
However, such a shade roller suffers a serious drawback concerning parts kept in stock for manufacturing of the rollers, because the various size requirements of the windows means manufacturers will need to have all sizes of the rollers to fulfill the needs. Such need for comprehensive stocks of parts incurs extra expenses of manufacturing different sizes of rollers, leasing for a warehouse for storing products, etc.
To solve such a problem of excessive stocks, there is provided a shade roller structure as shown in FIG. 6. The shade roller 80 includes a roller 81, a first tube 90 slidably received within the roller 81, a positioning cap 82 securely mounted to a first end of the roller 81, a knob 91 pivotally connected to a first end of the first tube 90, a first U-shaped rod 83 and a second U-shaped rod 92. A first end (not numbered) of the first U-shaped rod 83 is respectively inserted into the positioning cap 92 and the roller 81 and a coil spring 85 is securely mounted onto a portion 84 of the first U-shaped rod 83 which is inserted into the roller 81. A first end of the second U-shaped rod 92 is respectively inserted into the knob 91 and a part of the first tube 90 which extends out from the roller 81. A shade 95 is wound around a shaft (not numbered) combined by the roller 84 and an extension of the first tube 90. Second ends of the first U-shaped rod 83 and of the second U-shaped rod 92 are respectively and securely provided with one of a pair of brackets 86, 94. Therefore, when both of the brackets 86, 94 are securely attached on a surface such as a wall and the shade roller structure extends therebetween, the shade 95 is able to be pulled down by a user and the shade 95 is then able to be positioned by a bracket (not shown) whenever a desired length of the shade 95 is reached. When the user needs to roll up the shade 95, he/she simply pulls down the shade 95 to disengage the limitation of the bracket, then the shade 95 will be rolled back by a recovery force created by the coil spring 85. It is to be noted that due to the first tube having the adaptability of different widths, the structure solves the over stocking problems. However, if the first tube 90 is to be slidably received within the roller 81, a diameter of the first tube 90 must be smaller than that of the roller 81, such that a circumferential surface combined with the roller 81 and the first tube 90 is inclined toward the knob 91, which shows no difference when the shade 95 is completely pulled out from the shaft, but a great difference when the shade 95 is partly pulled out and partly is still wound around the shaft. Due to the inclination of the shaft, the shade 95 will not be wound around the shaft evenly, which spoils the appearance of the blind, the window and a view therethrough.
From the previous description, it is noted that to fully solve the aforementioned problems, alternatives and/or improvement(s) to the conventional shade rollers are thus required. A shade roller constructed in accordance with the present invention tends to mitigate and/or obviate the aforementioned problems.